Two women in their 20s will appear in a Belfast court charged with brothel-keeping and possessing criminal property as part of a cross-border joint police operation against organised prostitution across Ireland.

The women who are aged 23 and 27 will appear alongside another 27-year-old woman who has been charged with obstructing the police.

Two other women, whom the Police Service of Northern Ireland arrested in Tuesday's operation, have been released on bail pending further inquiries.

Eight people in total were arrested as part of the joint investigation carried out by the Garda Síochána in the south and the PSNI in the north.

Searches were carried out at more than 120 houses, apartments and flats on both sides of the border. Some of the premises were being used as brothels, the police said.

The PSNI said three suspected victims of human trafficking have been rescued and taken to places of safety.

Gardaí said the operation was cross-border because prostitution operates on a cross-border basis and victims of trafficking and prostitution are regularly moved around brothels in both jurisdictions.

PSNI Detective Superintendent Philip Marshall said: "We are determined to do something about this problem. It is not something society should stand for, it is a criminal offence and police do take it seriously."

He said Wednesday's events demonstrated the commitment of the PSNI, gardaí and other law enforcement agencies across Europe.

The operation south of the border, which involved more than 200 officers, was led by members of the Organised Crime Unit based at the National Bureau of Criminal Investigation supported by officers from all regions.

A man in his 40s and a woman in her 20s are being questioned at Dundrum garda station, and a woman in her 20s is being held in Store Street garda station.

A garda spokesman said: "During the investigation to date it has been established that prostitution is organised on a cross-border basis and today's joint operation was specifically aimed at individuals and groups intent on making profits from vulnerable members of society across the island of Ireland.

"The policy of An Garda Síochána is to treat women involved as witnesses/victims unless significant evidence comes to light suggesting direct involvement in organised prostitution or brothel-keeping.

"Specific training has been provided to gardaí investigating this type of crime who continue to liaise closely with various support groups working in this area."